Hydrogen Embrittlement of Amorphous Fe-Cr-Mo Alloys

Abstract The effects of corrosion resistance and metalloid additives on hydrogen embrittlement of amorphous Fe-Cr-Mo alloys containing different amounts of Cr, C, B, and P were studied by bending and tensile tests mainly in 1N HCl at 30 C. Analysis of fracture surfaces was also attempted. The susceptibility to embrittlement was greatly affected by chromium content and metalloid additives. An increase in chromium content from 5 to 10 At.% decreased both the corrosion rate and susceptibility to embrittlement. The embrittlement was accelerated by carbon but not by boron and phosphorus. The fracture surfaces of embrittled amorphous specimens seemed to consist of Wallner lines. The crack velocity calculated from Wallner lines was in the range of 0.4 to 0.5 times the velocity of transverse elastic wave.